Optical coherence tomography device, method, and system

ABSTRACT

In accordance with one aspect of the present invention, an optical coherence tomography instrument comprises an eyepiece for receiving at least one eye of a user is provided; a light source that outputs light that is directed through the eyepiece into the user&#39;s eye; an interferometer configured to produce optical interference using light reflected from the user&#39;s eye; an optical detector disposed so as to detect said optical interference; and electronics coupled to the detector. The electronics can be configured to perform a risk assessment analysis based on optical coherence tomography measurements obtained using the interferometer. An output device can be electrically coupled to the electronics, and may be configured to output the risk assessment to the user through the output device. The optical coherence tomography instrument can be self-administered, and the eyepiece can be a monocular system or a binocular system.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of, and claims the benefit of, U.S.patent application Ser. No. 12/111,894, titled “OPTICAL COHERENCETOMOGRAPHY DEVICE, METHOD, AND SYSTEM” and filed on Apr. 29, 2008, thedisclosure of which is hereby incorporated by reference in its entirety.U.S. patent application Ser. No. 12/111,894 claims the benefit of U.S.Provisional Application No. 61/040,084, titled, “OPTICAL COHERENCETOMOGRAPHY DEVICE, METHOD, AND SYSTEM,” and filed Mar. 27, 2008, whichis hereby incorporated by reference in its entirety, including withoutlimitation, for example, the optical coherence tomography devices,methods, and systems disclosed therein.

BACKGROUND

1. Field

Embodiments of the invention relate to the field of optical coherencetomography and, in particular, to devices, systems, methods of utilizingsuch optical coherence tomography data to perform precision measurementson eye tissue for the detection of eye diseases.

2. Description of the Related Art

Many industrial, medical, and other applications exist for opticalcoherence tomography (OCT), which generally refers to aninterferometric, non-invasive optical tomographic imaging techniqueoffering millimeter penetration (approximately 2-3 mm in tissue) withmicrometer-scale axial and lateral resolution. For example, in medicalapplications, doctors generally desire a non-invasive, in vivo imagingtechnique for obtaining sub-surface, cross-sectional and/orthree-dimensional images of translucent and/or opaque materials at aresolution equivalent to low-power microscopes. Accordingly, in thecoming years, it is projected that there will be 20 million OCT scansperformed per year on patients. Most of these will probably occur in thefield of ophthalmology. In current optical coherence tomography systems,doctors or other medical professionals administer the OCT scans in thedoctors' medical office or medical facilities.

SUMMARY

Various embodiments of the present invention relate to the utilizationof optical coherence tomography, which generally refers to aninterferometric, non-invasive optical tomographic imaging technique,that can be used to detect and analyze, for example, eye tissue, and/ordisease features, including but not limited to cystoid retinaldegeneration, outer retinal edema, subretinal fluid, subretinal tissue,macular holes, drusen, or the like. For example, and in accordance withone aspect of the present invention, an optical coherence tomographyinstrument comprises an eyepiece for receiving at least one eye of auser; a light source that outputs light that is directed through theeyepiece into the user's eye; an interferometer configured to produceoptical interference using light reflected from the user's eye; anoptical detector disposed so as to detect said optical interference;electronics coupled to the detector and configured to perform a riskassessment analysis based on optical coherence tomography measurementsobtained using said interferometer; and an output device electricallycoupled to the electronics, and the output device may be configured tooutput the risk assessment to the user through the output device.Generally, the optical coherence tomography instruments, devices,systems, and methods disclosed herein can be self-administered, and theeyepiece can be a monocular system or a binocular system.

In accordance with another aspect of the present invention, an opticalcoherence tomography instrument comprises first and second oculars forreceiving a pair of eyes of a user; a light source that outputs lightthat is directed through the first and second oculars to the user'seyes; an interferometer configured to produce optical interference usinglight reflected from the user's eye; an optical detector disposed so asto detect said optical interference; and electronics coupled to thedetector and configured to provide an output to a user based on opticalcoherence tomography measurements obtained using said interferometer.

In other aspects of the present invention, an optical coherencetomography instrument comprises an eyepiece for receiving at least oneeye of a user; a light source that outputs a beam that is directedthrough the eyepiece to the user's eye; an interferometer configured toproduce optical interference using light reflected from the user's eye;an optical detector disposed so as to detect said optical interference;a electronics coupled to the detector and configured to automaticallyperform a diagnosis based on optical coherence tomography measurementsobtained using said interferometer; and an output device electricallycoupled to the electronics, said output device configured to output thediagnosis to the user through the output device.

In accordance with another aspect of the present invention, an opticalcoherence tomography instrument for providing self-administered diseasescreening, said instrument comprises an eyepiece for receiving at leastone eye of a user; a light source that outputs a beam that is directedthrough the eyepiece to the user's eye; an interferometer configured toproduce optical interference using light reflected from the user's eye;an optical detector disposed so as to detect said optical interference;a processor in communication with the detector and configured toidentify one or more diseases that the user may manifest indications ofbased on optical coherence tomography measurements obtained using saidinterferometer; and an output device electrically coupled to theelectronics, said output device configured to alert the user.

In other aspects of the present invention, an optical coherencetomography instrument comprises an eyepiece for receiving at least oneeye of a user; at least one target display visible through saideyepieces; a light source that outputs light that is directed throughthe eyepiece to the user's eye; an interferometer configured to produceoptical interference using light reflected from the user's eye; anoptical detector disposed so as to detect said optical interference; andelectronics coupled to the target display and said detector andconfigured to provide an output to a user based on optical coherencetomography measurements obtained using said interferometer, wherein saidelectronics is further configured to produce features on said targetdisplay of varying size and receive user responses to test a user'svisual acuity.

In accordance with another aspect of the present invention, an opticalcoherence tomography instrument comprises an eyepiece for receiving atleast one eye of a user; a light source that outputs light that isdirected through the eyepiece to the user's eye; an interferometerconfigured to produce optical interference using light reflected fromthe user's eye; an optical detector disposed so as to detect saidoptical interference; electronics coupled to the detector and configuredto provide an output to a user based on optical coherence tomographymeasurements; and a card reader configured to receive a card from saiduser, said card reader in communication with said electronics totransmit signals thereto to authorize said electronics to provide theoutput to said user.

In other aspects of the present invention, an optical coherencetomography instrument comprises an eyepiece for receiving at least oneeye of a user; a light source that outputs light that is directedthrough the eyepiece to the user's eye; an interferometer configured toproduce optical interference using light reflected from the user's eye;an optical detector disposed so as to detect said optical interference;electronics coupled to the detector and configured to provide an outputto a user based on optical coherence tomography measurements obtainedusing said interferometer; memory that includes a list of healthcareproviders; and an output device electrically coupled to the electronicsto provide an output to said user, wherein said electronics isconfigured to access said memory to provide at least a portion of saidlist in said output to said user.

In accordance with another aspect of the present invention, an opticalcoherence tomography instrument comprises an eyepiece for receiving atleast one eye of a user; a light source that outputs light that isdirected through the eyepiece to the user's eye; an interferometerconfigured to produce optical interference using light reflected fromthe user's eye; an optical detector disposed so as to detect saidoptical interference; electronics coupled to the detector and configuredto provide an output to a user based on optical coherence tomographymeasurements obtained using said interferometer; and an output deviceelectrically coupled to the electronics and configured to provide anoutput to said user, wherein said electronics is configured to provide arecommended deadline for consulting a healthcare provider based on thepatient's risk level of having certain types of diseases as determinedusing said optical coherence tomography measurements.

In other aspects of the present invention, an optical coherencetomography instrument comprises an eyepiece for receiving an eye of auser; a light source that outputs a light beam that is directed throughthe eyepiece to the user's eye; an interferometer configured to produceoptical interference using light reflected from the user's eye; anoptical detector disposed so as to detect said optical interference; anarray of display elements visible to the user through the eyepiece, saidarray of display elements configured to display a display target atdifferent locations across the array; and electronics in communicationwith said array of display elements and said detector, said electronicsconfigured to use said position of said display target on said array ofdisplay elements to associate optical coherence tomography measurementswith spatial locations.

In accordance with another aspect of the present invention, an opticalcoherence tomography instrument comprises an eyepiece for receiving asubject's eye; a light source that outputs light that is directedthrough the eyepiece to the subject's eye; an interferometer configuredto produce optical interference using light reflected from the user'seye; an optical detector disposed so as to detect said opticalinterference; and memory including statistical information correlatingoptical coherence tomography measurements with risk of at least onedisease; electronics coupled to the detector and configured to accesssaid memory to compare data obtained based on optical coherencetomography measurements of said subject's eye using said interferometerwith said statistical information to provide an assessment of saidsubject's risk of having said at least one disease.

In other aspects of the present invention, an optical coherencetomography instrument comprises an eyepiece for receiving an eye of auser; a light source that outputs light that is directed through theeyepiece to the user's eye; an adjustable optical element configured toalter the focus of the light directed into the user's eye; aninterferometer configured to produce optical interference using lightreflected from the user's eye; an optical detector disposed so as todetect said optical interference; electronics coupled to the detectorand configured to provide an output to a user based on optical coherencetomography measurements obtained using said interferometer; and anoutput device electrically coupled to the electronics and configured toprovide an output to said user, wherein said electronics is configuredto adjust said optical element to focus said light using a signal fromsaid detector.

For purposes of this summary, certain aspects, advantages, and novelfeatures of the invention are described herein. It is to be understoodthat not necessarily all such aspects, advantages, and features may beemployed and/or achieved in accordance with any particular embodiment ofthe invention. Thus, for example, those skilled in the art willrecognize that the invention may be embodied or carried out in a mannerthat achieves one advantage or group of advantages as taught hereinwithout necessarily achieving other advantages as may be taught orsuggested herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features, aspects and advantages of the presentinvention are described in detail below with reference to the drawingsof various embodiments, which are intended to illustrate and not tolimit the invention. The drawings comprise the following figures inwhich:

FIG. 1 is a schematic diagram of one embodiment of the optical coherencetomography system described herein.

FIG. 2 is a schematic diagram of one embodiment of an interferometerarranged to perform measurements of an eye.

FIG. 3A is a schematic diagram of one embodiment of an OCT systemcomprising a main body configured to conveniently interfere with aperson's eyes, the main body being in communication with various systemsas described herein.

FIG. 3B is a perspective view schematically illustrating an embodimentof the main body shown in FIG. 3A.

FIG. 4 is schematic diagram of one embodiment of a spectrometer used toanalyze data from an interferometer used for OCT.

FIG. 5 is a schematic diagram of the main body of an OCT systemcomprising a single display for presenting a display target to apatient.

FIGS. 6A-6C are schematic diagrams illustrating the use of opticalcoherence tomography to scan retinal tissue to generate A-scans andB-scans.

FIGS. 7A-7F are schematic diagrams illustrating embodiments foradjusting and/or calibrating interpupillary distance.

FIG. 8 is a block diagram schematically illustrating one embodiment ofthe computer system of the optical coherence tomography system describedherein.

FIG. 9 is illustrates a process flow diagram of one embodiment ofperforming precision measurements on retinal tissue for the detection ofpathognomonic disease features.

FIGS. 10A-10D illustrate possible embodiments of disposing the main bodyof an optical coherence tomography device with respect to a user.

FIGS. 11A-11B illustrate possible embodiments of output reportsgenerated by the optical coherence tomography device.

FIG. 12 is a block diagram schematically illustrating another embodimentof the computer system for a optical coherence tomography systemdescribed herein.

FIG. 13 is a block diagram schematically illustrating components in oneembodiment of the computer system for an optical coherence tomographysystem described herein.

FIG. 14A is a diagram schematically illustrating one embodiment fordetermining a risk assessment.

FIG. 14B is a schematic illustration of a plot of risk of retinaldisease versus retinal thickness for determining a risk assessment inanother embodiment.

FIG. 15 is an illustration of RPE detection and RPE polynomial fitcurvature, and the difference there between.

FIG. 16 is an illustration of retinal tissue segmented into inner andouter retinal tissue regions.

DETAILED DESCRIPTION

Embodiments of the invention will now be described with reference to theaccompanying figures, wherein like numerals refer to like elementsthroughout. The terminology used in the description presented herein isnot intended to be interpreted in any limited or restrictive manner,simply because it is being utilized in conjunction with a detaileddescription of certain specific embodiments of the invention.Furthermore, embodiments of the invention may comprise several novelfeatures, no single one of which is solely responsible for its desirableattributes or which is essential to practicing the inventions hereindescribed.

The embodiments described herein make OCT screening more accessible tousers thereby allowing for earlier detection and/or treatment of variousdiseases, ailments, or conditions, for example, maculopathy, glaucoma,or the like.

The terms “optical coherence tomography” and “OCT” generally refer to aninterferometric technique for imaging samples, in some cases, withmicrometer lateral resolution. This non-invasive optical tomographicimaging technique is used in ophthalmology to provide cross-sectionalimages of the eye, and more particularly the posterior of the eye,though it can also be used to image other samples or tissues in areas ofthe user's body.

Generally, OCT employs an interferometer. Light from a light source (forexample, a broadband light source) is split (for example, by abeamsplitter) and travels along a sample arm (generally comprising thesample) and a reference arm (generally comprising a mirror). A portionof the light from the sample arm is reflected by the sample. Light isalso reflected from a mirror in the reference arm. (Light from the testarm and the reference arm is recombined, for example by thebeamsplitter.) When the distance travelled by light in the sample arm iswithin a coherence length of the distance travelled by light in thereference arm, optical interference occurs, which affects the intensityof the recombined light. The intensity of the combined reflected lightvaries depending on the sample properties. Thus, variations for theintensity of the reflectance measured are indications of the physicalfeatures of the sample being tested.

In time-domain OCT, the length of the reference arm can be varied (forexample, by moving one or more reference mirrors). The reflectanceobserved as the reference arm distance changes indicates sampleproperties at different depths of the sample. (In some embodiments, thelength of the sample arm is varied instead of or in addition to thevariation of the reference arm length.) In frequency-domain OCT, thedistance of the reference arm can be fixed, and the reflectance can thenbe measured at different frequencies. For example, the frequency oflight emitted from a light source can be scanned across a range offrequencies or a dispersive element, such as a grating, and a detectorarray may be used to separate and detect different wavelengths. Fourieranalysis can convert the frequency-dependent reflectance properties todistance-dependent reflectance properties, thereby indicating sampleproperties at different sample depths. In certain embodiments, OCT canshow additional information or data than nonmydriatic color fundusimaging.

The term “A-scan” describes the light reflectivity associated withdifferent sample depths. The term “B-scan” as used herein refers to theuse of cross-sectional views of tissues formed by assembly of aplurality of A-scans. In the case of ophthalmology, light reflected byeye tissues is converted into electrical signals and can be used toprovide data regarding the structure of tissue in the eye and to displaya cross-sectional view of the eye. In the case of ophthalmology, A-scansand B-scans can be used, for example, for differentiating normal andabnormal eye tissue or for measuring thicknesses of tissue layers in theeyes.

In ophthalmic instances, an A-scan can generally include data from thecornea to the retina, and a B-scan can include cross-sectional data froma medial border to a lateral border of the eye and from the cornea tothe retina. Three-dimensional C-scans can be formed by combining aplurality of B-scans.

As used herein the terms “user” or “patient” may be usedinterchangeably, and the foregoing terms comprise without limitationhuman beings, whether or not under the care of a physician, and othermammals.

The terms “eye scan,” “scanning the eye,” or “scan the eyes,” as usedherein, are broad interchangeable terms that generally refer to themeasurement of any part or substantially all of the eye, including butnot limited to the cornea, the retina, the eye lens, the iris, opticnerve, or any other tissue or nerve related to the eye.

The terms “risk assessment” and “diagnosis,” may be used in thespecification interchangeably although the terms have differentmeanings. The term “risk assessment” generally refers to a probability,number, score, grade, estimate, etc. of the likelihood of the existenceof one or more illnesses, diseases, ailments, or the like. The term“diagnosis” generally refers to a determination by examination and/ortests the nature and circumstances of an illness, ailment, or diseasedcondition.

The disclosure herein provides various methods, systems, and devices forgenerating and utilizing optical coherence tomography image data toperform precision measurements on retinal tissue for the detection ofdisease features, and generating a risk assessment and/or diagnosisbased on data obtained by optical coherence tomography imagingtechniques. These methods, systems and devices may employ, in someembodiments, a statistical analysis of the detected disease featuresobtained by optical coherence tomography imaging techniques. Suchmethods, systems, and devices can be used to screen for diseases.

With reference to FIG. 1, there is illustrated a block diagram depictingone embodiment of the optical coherence tomography system. In oneembodiment, computer system 104 is electrically coupled to an outputdevice 102, a communications medium 108, and a user card reader system112. The communications medium 108 can enable the computer system 104 tocommunicate with other remote systems 110. The computer system 104 maybe electrically coupled to main body 106, which the user 114 positionsnear or onto the user's eyes. In the illustrated example, the main body106 is a binocular system (for example, has a two oculars or opticalpaths for the eyes providing one view for one eye and another view foranother eye, or the like) configured to scan two eyes withoutrepositioning the oculars with respect to the head of the patient,thereby reducing the time to scan a patient. In some embodiments, theeyes are scanned simultaneously using a scanner (for example,galvanometer), which provides interlaces of measurements from both eyes.Other embodiments are possible as well, for example, the binocularsystem or a two ocular system having two respective optical paths to thetwo eyes can be configured to scan the eyes in series, meaning one eyefirst, and then the second eye. In some embodiments, serial scanning ofthe eyes comprises scanning a first portion of the first eye, a firstportion of the second eye, a second portion the first eye, and so on.Alternatively, the main body 106 can comprise a monocular system or oneocular system or optical path to the eye for performing eye scans.

Referring to FIG. 1, the user 114 can engage handle 118 and position(for example, up, down, or sideways) the main body 106 that is at leastpartially supported and connected to a zero gravity arm 116, andaccordingly the system 100 has no chin rest. In some embodiments, thisconfiguration can introduce positioning error due to movement of themandible. When the main body 106 is in such a position, the distancebetween the outermost lens (the lens closest to the user) and the user'seye can range between 10 mm and 30 mm, or 5 mm and 25 mm, or 5 mm and 10mm. The close proximity of the lens system to the user's eyes increasescompactness of the system, reduces position variability when the patientplaces his eyes (for example, orbital rims) against the man body, andincreases the viewing angle of the OCT apparatus when imaging through anundilated pupil. Accordingly, the main body 106 can also compriseeyecups 120 (for example, disposable eyecups) that are configured tocontact the user's eye socket to substantially block out ambient lightand/or to at least partially support the main body 106 on the eye socketof the user 114. The eyecups 120 have central openings (for example,apertures) to allow passage of light from the light source in theinstrument to the eyes. The eyecups 120 can be constructed of paper,cardboard, plastic, silicon, metal, latex, or a combination thereof. Theeyecups 120 can be tubular, conical, or cup-shaped flexible orsemi-rigid structures with openings on either end. Other materials,shapes and designs are possible. In some embodiments, the eyecups 120are constructed of latex that conforms around eyepiece portions of themain body 106. The eyecups 120 are detachable from the main body 106after the eye scan has been completed, and new eyecups 120 can beattached for a new user to ensure hygiene and/or to protect against thespread of disease. The eyecups 120 can be clear, translucent or opaque,although opaque eyecups offer the advantage of blocking ambient lightfor measurement in lit environments.

The main body 106 may comprise one or more eyepieces, an interferometer,one or more target displays, a detector and/or an alignment system. Theoptical coherence tomography system may comprise a time domain opticalcoherence tomography system and/or a spectral domain optical coherencetomography system. Accordingly, in some embodiments, the main body 106comprises a spectrometer, (for example, a grating) and a detector array.The main body may, in some embodiments, comprise signal processingcomponent (for example, electronics) for performing, for example,Fourier transforms. Other types of optical coherence tomography systemsmay be employed.

FIG. 2 shows a diagram of an example optical coherence tomographysystem. Light 150 is output from a light source 155. The light source155 may comprise a broadband light source, such as a superluminescentdiode or a white light source. (Alternatively, light emitted from thelight source 155 may vary in frequency as a function of time.) The light150 may comprise collimated light. In one embodiment, light 150 from thelight source 155 is collimated with a collimating lens. The light issplit at beamsplitter 160. Beamsplitters, as described herein, maycomprise without limitation a polarization-based beamsplitter, atemporally based beamsplitter and/or a 50/50 beamsplitter or otherdevices and configurations. A portion of the light travels along asample arm, directed towards a sample, such as an eye 165 of a user 114.Another portion of the light 150 travels along a reference arm, directedtowards a reference mirror 170. The light reflected by the sample andthe reference mirror 170 are combined at the beamsplitter 160 and sensedeither by a one-dimensional photodetector or a two-dimensional detectorarray such as a charge-coupled device (CCD) or complementarymetal-oxide-semiconductor (CMOS). A two-dimensional array may beincluded in a full field OCT instrument, which may gather informationmore quickly than a version that uses a one dimensional photodetectorarray instead. In time-domain OCT, the length of the reference arm(which may be determined in part by the position of the reference mirror170) may be varying in time.

Whether interference between the light reflected by the sample and thelight reflected by the reference mirror/s occurs will depend on thelength of the reference arm (as compared to the length of the test arm)and the frequency of the light emitted by the light source. Highcontrast light interference occurs between light travelling similaroptical distances (for example, (differences less than a coherencelength). The coherence length is determined by the bandwidth of thelight source. Broadband light sources correspond to smaller coherencelengths.

In time-domain OCT, when the relative length of the reference and samplearms varies over time, the intensity of the output light may be analyzedas a function of time. The light signal detected results from light raysscattered from the sample that interfere constructively with lightreflected by the reference mirror/s. Increased interference occurs,however, when the lengths of the sample and reference arms areapproximately similar (for example, within about one coherence length insome cases). The light from the reference arm, therefore, will interferewith light reflected from a narrow range of depths within the sample. Asthe reference (or sample) arms are translated, this narrow range ofdepths can be moved through the thickness of the sample while theintensity of reflected light is monitored to obtain information aboutthe sample. Samples that scatter light will scatter light back thatinterferes with the reference arm and thereby produce an interferencesignal. Using a light source having a short coherence length can provideincreased to high resolution (for example, 0.1-10 microns), as theshorter coherence length yields a smaller range of depths that is probedat a single instant in time.

In various embodiments of frequency-domain optical coherence tomography,the reference and sample arms are fixed. Light from a broadband lightsource comprising a plurality of wavelengths is reflected from thesample and interfered with light reflected by the reference mirror/s.The optical spectrum of the reflected signal can be obtained. Forexample, the light may be input to a spectrometer or a spectrographcomprising, for example, a grating and a detector array, that detectsthe intensity of light at different frequencies.

Fourier analysis performed, for example, by a processor may convert datacorresponding to a plurality of frequencies to that corresponding to aplurality of positions within the sample. Thus, data from a plurality ofsample depths can be simultaneously collected without the need forscanning of the reference arm (or sample) arms. Additional detailsrelated to frequency domain optical coherence tomography are describedin Vakhtin et al., (Vakhtin A B, Kane D J, Wood W R and Peterson K A.“Common-path interferometer for frequency-domain optical coherencetomography,” Applied Optics. 42(34), 6953-6958 (2003)).

Other methods of performing optical coherence tomography are possible.For example, in some embodiment of frequency domain optical coherencetomography, the frequency of light emitted from a light source varies intime. Thus, differences in light intensity as a function of time relateto different light frequencies. When a spectrally time-varying lightsource is used, a detector may detect light intensity as a function oftime to obtain optical spectrum of the interference signal. The Fouriertransform of the optical spectrum may be employed as described above. Awide variety of other techniques are also possible.

FIG. 3A shows one configuration of main body 106 comprising an opticalcoherence tomography system and an alignment system. Other opticalcoherence tomography systems and/or alignment systems may be included inplace of or in addition to the systems shown in FIG. 3A. As shown, themain body 106 can include two eyepieces 203, each eyepiece configured toreceive an eye from a user 114. In other embodiments, the main body 106includes only one eyepiece 203.

FIG. 3A shows one representative embodiment of an optical coherencetomography system. Light from a light source 240 may propagate along apath that is modulated, for example, vertically and/or horizontally byone or more beam deflectors 280. A galvanometer may be used for thispurpose. The galvanometer 280 can control the horizontal and/or verticallocation of a light beam from the light source 240, thereby allowing aplurality of A-scans (and thus one or more B-scan and/or a C-scan) to beformed.

The light from the light source 240 is split at beamsplitter 245. Insome embodiments, beamsplitter 245 is replaced by a high frequencyswitch that uses, for example, a galvanometer, that directs about 100%of the light towards mirror 250 a for about ½ of a cycle and thendirects about 100% of the light towards mirror 250 b for the remainderof the cycle. The light source 240 may include a broadband light source,such as a superluminescent light-emitting diode. Light split at thebeamsplitter 245 is then split again at beamsplitter 285 a or 285 b toform a reference arm and a sample arm. A first portion of the lightsplit at beamsplitter 285 a or 285 b is reflected by reference mirrors273 a or 273 b, reference mirrors 270 a or 270 b, and reference mirrors265 a or 265 b. A second portion of the light split at beamsplitter 285a or 285 b is reflected by mirror 250 a or 250 b, by mirror 255 a or 255b and by mirror 260 a or 260 b. Mirrors 255 a or 255 b and mirrors 250 aand 250 b are connected to a Z-offset adjustment stage 290 b. By movingthe position of the adjustment stage 290 a or 290 b, the length of thesample arm is adjusted. Thus, the adjustment stage 290 a or 290 b canadjust the difference between the optical length from the light source240 to a portion of the sample and the optical length from the lightsource 240 and the reference mirror 270 a or 270 b and/or referencemirror 273 a or 273 b. This difference can be made small, for example,less than a coherence length, thereby promoting for optical interferenceto occur. In some embodiments, the positions of one or more referencemirrors (for example, reference mirror 270 a or 270 b and referencemirror 273 a or 273 b) are movable in addition to or instead of theadjustment stage being movable. Thus, the length of the reference armand/or of the sample arm may be adjustable. The position of theadjustment stages 290 a and/or 290 b may be based on the signals fromthe device, as described in more detail below.

The light reflected by mirror 260 a or 260 b is combined with light fromdisplay 215 a or 215 b at beamsplitter 230 a or 230 b. The displays 215a and 215 b may comprise one or more light sources, such as in anemissive display like an array of matrix LEDs. Other types of displayscan be used. The display can display targets of varying shapes andconfigurations, including a bar and/or one or more dots. A portion ofthe optical path from the light source 240 to the eye may be coaxialwith a portion of the path from the displays 215 a and 215 b to the eye.These portions may extend though the eyepiece. Accordingly, a light beamfrom the light source 240 is coaxial with a light beam from the displays215 a and 215 b such that the eyes can be positioned and aligned withrespect to the eyepieces using the displays.

As described in greater detail below, for example, the user 114 may useimages from the displays in order to adjust interpupillary distance. Invarious embodiments, for example, proper alignment of two imagespresented by the displays may indicate that the interpupillary distanceis appropriately adjusted. Thus, one or more adjustment controls 235 maybe used to adjust the distance between the display targets 215 a and 215b and/or between the eyepieces 203. The adjustment controls 235 may beprovided on the sides of the main body 106 or elsewhere. In certainembodiments, the adjustment control 204 may comprise a handle on themain body 106, as shown in FIG. 3B. In this embodiment, rotation of theadjustment control 204 may increase or decrease the interpupillarydistance.

The combined light (that is reflected by mirror 260 a or 260 b and thatcomes from display 215 a or 215 b) is focused by adjustable poweredoptics (for example, lens) 210 possibly in conjunction with opticalelement 205. The adjustable optics 210 may comprise a zoom lens or lenssystem that may be have, for example, a focal length and/or power thatis adjustable. The adjustable optics 210 may comprise be part of anauto-focus system or may be manually adjusted. The adjustable optics 210may provide optical correction for those in need of such correction (forexample, a user whose glasses are removed during testing). The positionof the powered optics 210 may be based on the signals obtained from thedevice, as described in more detail below. The focused light thentravels through eyepiece windows or lens 205, positioned at a proximalend of the eyepiece 203, towards the eye of a user 114. In the casewhere a lens 205 is includes, this lens 205 may contribute to focusingof the light into the eye.

This light focused into the eye may be scattered by tissue or featurestherein. A portion of this scattered light may be directed back into theeyepiece. Lens 205 may thus receive light 207 reflected from the user'seye, which travels through the powered optics 210, reflects off of thebeamsplitter 230 a or 230 b towards beamsplitter 220 a or 220 b, whichreflects the light towards mirrors 295 a or 295 b. At 295 a or 295 b,light reflected by the sample interferes with light in the reference arm(path between beamsplitter 285 a or 285 b and beamsplitter 295 a or 295b that includes mirrors 273 a or 273 b and 270 a or 270 b).(Accordingly, the sample arm includes the optical path betweenbeamsplitter 285 a or 285 b and beamsplitter 295 a or 295 b thatincludes mirrors 250 a or 250 b and 255 a or 255 b and the sample oreye.) The light is then reflected by mirror 225 a or 225 b towardsswitch 275. In some embodiments, the switch 275 comprises a switchabledeflector that switches optical paths to the first or second eye tocollect data from the respective eye to be sent to the data acquisitiondevice 202. The switch may comprise a low-frequency switch, such thatall data to be collected from one eye is obtained before the data iscollected from the other eye. Alternatively, the switch may comprise ahigh-frequency switch, which may interlace data collected from each eye.

The instrument may be configured differently. For example, a commonreference path may be used for each eye. In some embodiments, thereference arm includes one or more movable mirrors to adjust the opticalpath length difference between the reference and sample arms. Componentsmay be added, removed, or repositioned in other embodiments. Othertechniques, may be used.

Although not shown, for example, polarizers and polarizing beamspittersmay be used to control the propagation of light through the optical pathin the optical system. Other variations are possible. Other designs maybe used.

In some embodiments, an A-scan may be formed in the time domain. Inthese instances, the Z-offset adjustment stage and corresponding mirror255 a or 255 b and mirror 255 a or 255 b may change positions in time.Alternatively, reference mirrors 270 a and 270 b and reference mirrors273 a and 273 b or other mirrors in the reference or sample arms may betranslated. The combined light associated with various mirror positionsmay be analyzed to determine characteristics of an eye as a function ofdepth. In other embodiments, an A-scan may be formed in the spectraldomain. In these instances, the frequencies of the combined light may beanalyzed to determine characteristics of an eye as a function of depth.Additionally, one or more galvanometers 280 can control the horizontaland/or vertical location of the A-scan. Thus, a plurality of A-scans canbe obtained to form a B-scan and/or a C-scan.

Light output from the structure 275 can be input into a data acquisitiondevice 202, which may comprise, for example, a spectrometer or a lightmeter. A grating may be in the main body 106. The data acquisitiondevice 202 is coupled to a computer system 104, which may present outputbased on scans to the user 114. The output device may include a monitorscreen, in which output results are displayed. The output device mayinclude a printer, which prints output results. The output device may beconfigured to store data on a portable medium, such as a compact disc orUSB drive, or a custom portable data storage device.

In some embodiments, the computer system 104 analyzes data received bythe data acquisition device 202 in order to determine whether one ormore of the adjustment stages 290 a and/or 290 b and/or the poweredoptics 210 should be adjusted. In one instance, an A-scan is analyzed todetermine a position (for example, a coarse position) of the retina suchthat data on the retina may be obtained by the instrument. In someembodiments, each A-scan comprises a plurality of light intensityvalues, each associated with a different depth into the sample. TheA-scan may be obtained, in some embodiments, by translating the Zadjustment stage 290 a or 290 b. Likewise, the A-scan comprises valuesof reflected signal for obtained for different location of Z adjustmentstage. The retina reflects more light than other parts of the eye, andthus, it is possible to determine a position of the adjustment stage 290a or 290 b that effectively images the retina by assessing what depthsprovide an increase in reflected intensity. In some embodiments, the Zadjustment stage may be translated and the intensity values may bemonitored. An extended peak in intensity for a number of Z adjustmentstage positions may correspond to the retina. A variety of differentapproaches and values may be monitored to determine the location of theretina. For example, multiple A-scans may be obtained at differentdepths and the integrated intensity of each scan may be obtained andcompared to determine which depth provided a peak integrated intensity.In certain embodiments, intensity values within an A-scan can becompared to other values within the A-scan and/or to a threshold. Theintensity value corresponding to the preferred location may be greaterthan a preset or relative threshold and/or may be different from therest of the intensity values, (for example, by more than a specifiednumber of standard deviations). A wide variety of approaches may beemployed.

After the positions of the adjustment stages 290 a and 290 b have beendetermined, subsequent image analysis may be performed to account forvibration or movement of the user's head, eyes or retinas relative tothe light source 240. A feedback system such as a closed loop feedbacksystem may be employed in effort to provide a more stabilized signal inthe presence of such motion. The optical coherence tomography signal maybe monitored and feedback provided to, for example, one or moretranslation stages to compensate for such vibration or movement. In someembodiments, subsequent image analysis may be based on initial imageand/or detect changes in image characteristics. For example, the imageanalysis may determine that the brightest pixel within an A-scan hasmoved 3 pixels from a previous scan. The adjustment stage 290 a or 290 bmay thus be moved based on this analysis. Other approaches may be used.

In some instances, optical coherence tomography signals are used toadjust the powered optics 210 to provide for increased or improvedfocus, for example, when a patient needs refractive correction. Manyusers/patients, for example, may wear glasses and may be tested whilenot wearing any glasses. The powered optics 210 may be adjusted based onreflected signal to determine what added correction enhances signalquality or is otherwise an improvement. Accordingly, in someembodiments, a plurality of A-scans is analyzed in order to determine aposition for the powered optics 210. In some instances, a plurality ofA-scans is analyzed in order to determine a position for the poweredoptics 210. In some embodiments, this determination occurs after theposition of the adjustment stage 290 a or 290 b has been determined. Oneor more A-scans, one or more B-scans or a C-scan may be obtained foreach of a plurality of positions of the powered optics 210. These scansmay be analyzed to assess, for example, image quality. The position ofthe powered optics 210 may be chosen based on these image qualitymeasures.

The image quality measure may include a noise measure. The noise measuremay be estimated based on the distribution of different intensity levelsof reflected light within the scans. For example, lower signals may beassociated with noise. Conversely, the highest signals may be associatedwith a saturated signal. A noise measure may be compared to a saturationmeasure as in signal to noise ratios or variants thereof. The lowestreflectivity measured (referred to as a low measure or low value) mayalso be considered. In some embodiments, the positions of the adjustmentstages 290 a and/or 290 b and/or the powered optics 210 is determinedbased upon a signal-to-noise measure, a signal strength measure, a noisemeasure, a saturation measure, and a low measure. Different combinationsof these parameters may also be used. Values obtained by integratingparameters over a number of positions or scans, etc., may also be used.Other parameters as well as other image quality assessments may also beused.

In one embodiment, a noise value is estimated to be a reflected lightvalue for which approximately 75% of the measured reflected light isbelow and approximately 25% of the measured reflected light is above.The saturation value is estimated to be a reflected light value forwhich approximately 99% of the measured reflected light is below andapproximately 1% of the measured reflected light is above. A middlevalue is defined as the mean value of the noise value and the saturationvalue. An intensity ratio is defined as the difference between thesaturation value and the low value divided by the low value multipliedby 100. A tissue signal ratio is defined as the number of reflectedlight values between the middle value and the saturation value dividedby the number of reflected light values between the noise value and thesaturation value. A quality value is defined as the intensity ratiomultiplied by the tissue signal ratio. Additional details are described,for example, in Stein D M, Ishikawa H, Hariprasad R, Wollstein G,Noecker R J, Fujimoto J G, Schuman J S. A new quality assessmentparameter for optical coherence tomography. Br. J. Ophthalmol.2006;90;186-190. A variety of other approaches may be used to obtain afigure of merit to use to measure performance and adjust the instrumentaccordingly.

In the case of adjusting the adjustable power optics, 210, in someembodiments, a plurality of positions are tested. For example, thepowered optics may be continuously moved in defined increments towardsthe eyes for each scan or set of scans. Alternatively, the plurality ofpositions may depend on previously determined image quality measures.For example, if a first movement of the powered optics 210 towards theeye improved an image quality measure but a subsequent second movementtowards the eye decreased an image quality measure, the third movementmay be away from the eye. Accordingly, optical power settings may beobtained that improve and/or maintains an improved signal. This opticalpower setting may correspond to optical correction and increase focus ofthe light beam in the eye, for example, on the retina, in someembodiments.

As described above, various embodiments employ an arrangement wherein apair of oculars is employed. Accordingly, such adjustments, may beapplied to each of the eyes as a user may have eyes of different sizeand the retina may located at different depths and thus a pair of zadjust stages may be used in some embodiments. Similarly, a user mayhave different prescription optical correction for the different eyes. Avariety of arrangements may be employed to accommodate such needs. Forexample, measurements and/or adjustments may be performed and completedon one eye and subsequently performed and completed the other eye.Alternatively, the measurements and/or adjustments may be performedsimultaneously or interlaced. A wide variety of other variations arepossible.

FIG. 4 shows a diagram of a spectrometer 400 that can be used as a dataacquisition device 202 for a frequency domain OCT system. Light 405input into the spectrometer 400 is collected by collecting lens 410. Thecollected light then projects through a slit 415, after which it iscollimated by the collimating lens 420. The collimated light isseparated into various spectral components by a grating 425. The grating425 may have optical power to focus the spectral distribution onto animage plane. Notably, other separation components, such as a prism maybe used to separate the light. The separated light is then directed ontoa detector array by focusing lens 430, such that spectral components ofeach frequency from various light rays are measured.

A wide variety of OCT designs are possible. For example, frequency canbe varied with time. The reference and sample arms can overlap. In someembodiments, a reference arm is distinct from a sample arm, while inother embodiments, the reference arm and sample arm are shared. See, forexample, Vakhtin A B, Kane D J, Wood W R and Peterson K A. “Common-pathinterferometer for frequency-domain optical coherence tomography,”Applied Optics. 42(34), 6953-6958 (2003). The OCT arrangements shouldnot be limited to those described herein. Other variations are possible.

In some embodiments, as shown in FIG. 5, the main body 106 includes onlya single display target 215. Light from the display target 215 is splitat an x-prism 505. Notably, other optical devices that split the sourcelight into a plurality of light rays may be used. This split light isreflected at mirror 510 a or 510 b and directed towards the user 114.

The user may be directed to fixate on a display target 215 while one ormore galvanometers 280 move light from the light source 240 to image anarea of tissue. In some embodiments, the display targets 215 are movedwithin the user's field of vision while an area of tissue is imaged. Forexample, in FIG. 6A, a display target 215 may be moved horizontally (forexample, in the medial-lateral direction), such that a patient isdirected to look from left to right or from right to left. Meanwhile, avertical scanner (for example, galvanometer) allows the verticallocation (for example, in the superior-inferior) of the sample scanningto change in time. FIG. 6 shows an eye, which is directed to move in thehorizontal direction 605. Due to the vertical scanner, the scannedtrajectory 610 covers a large portion of the eye 600. Scanning in thevertical and horizontal directions can produce a C-scan. In someembodiments, continuous and/or regularly patterned A-scans are combinedto form a full scan for example, B-scan or C-scan. In other embodiments,discrete and/or random A-scans are combined to form the full scan.Systems configured such that users 114 are directed to move their eyesthroughout a scan may include fewer scanners than comparable systemsconfigured such that users 114 keep their eyes fixated at a stationarytarget. For example, instead of a system comprising both a vertical anda horizontal scanner, the user 114 may move his eyes in the horizontaldirection, thereby eliminating the need for a horizontal scanner.

FIG. 6B shows an example of an A scan. The A scan comprises the signalstrength (indicated by the brightness) as a function of depth for onehorizontal and vertical position. Thus, an A-scan comprises a pluralityof intensity values corresponding to different anterior-posteriorpositions. A plurality of A scans form a B scan. FIG. 6C shows a B-scan,in which the largest portion of the bright signal corresponds to retinaltissue and the elevated region under the retina corresponds to diseasedtissue within the eye.

With reference to FIG. 7A, there is illustrated an enlarged viewdepicting an embodiment of the main body 106 that is configured with ahandle 118 for adjusting the eyepieces to conform to the user'sinterpupillary distance. In the illustrative embodiment, the main body106 comprises a left eyepiece 712 and a right eyepiece 714 wherein eachis connected to the other by interpupillary distance adjustment device718. The interpupillary distance adjustment device 718 is coupled to thehandle 118, wherein the handle 118 is configured to allow the user toengage the handle 118 to adjust the distance between the left and righteyepieces 712, 714 to match or substantially conform to theinterpupillary distance between the eyes of the user.

Referring to FIG. 7A, the user can rotate, turn, or twist the handle 118to adjust the distance between the left and right eyepieces 712, 714 soas to match or substantially conform to the interpupillary distancebetween the eyes of the user. Alternatively, the handle 118 can beconfigured to move side to side to allow the user to adjust the distancebetween the left and right eyepieces 712, 714. Additionally, the handle118 can be configured to move forward and backward to allow the user toadjust the distance between the left and right eyepieces 712, 714. Inthe alternative, the handle 118 can be configured to move up and down toallow the user to adjust the distance between the left and righteyepieces 712, 714. In another embodiment, the distance between the leftand right eyepieces 712, 714 can be adjusted and/or controlled by amotor activated by the user. Alternatively, the motor can be configuredto be controlled by computer system 104 to semi-automatically positionthe left and right eyepieces 712, 714 to match the interpupillarydistance between the eyes of the user. In these instances, eye trackingdevices may be included with a system described herein. In otherembodiments, a combination of the foregoing are utilized to adjust thedistance between the left and right eyepieces 712, 714 to match orsubstantially conform to the user's interpupillary distance.

A user 114 may adjust interpupillary distance based on the user'sviewing of one or more fixation targets on one or more displays 215. Forexample, the displays 215 and the fixation targets may be configuredsuch that the user views two aligned images, which may form a single,complete image when the interpupillary distance is appropriate for theuser 114. The user 114 may adjust (for example, rotate) an adjustmentcontrol 204 to change the interpupillary distance based on the fixationtarget images, as shown in FIG. 7A. FIGS. 7B-7F illustrate oneembodiment of fixation targets as seen by the viewer under a pluralityof conditions; however, other fixation targets are possible, includingbut not limited to a box configuration. FIG. 7B shows a U-shapedfixation target 715 a on the display 215 a for the left eye. FIG. 7Cshows an upside-down U-shaped fixation target 715 b on the display 215 bfor the right eye.

When the interpupillary distance is appropriately adjusted, the bottomand top images 715 a and 715 b are aligned, as shown in FIG. 7D to forma complete H-shaped fixation target 715. When the interpupillarydistance is too narrow, the fixation target 715 a on the display 215 afor the left eye appear shifted to the right and the fixation target onthe display 215 b for the right eye appear shifted to the left and theuser sees the image shown in FIG. 7E. Conversely, when theinterpupillary distance is too wide, the fixation target 715 a on thedisplay 215 a for the left eye appear shifted to the left and thefixation target on the display 215 b for the right eye appear shifted tothe right and the user sees the image shown in FIG. 7F . Thus, theinterpupillary distance may be adjusted based on these images.

In particular, in FIG. 7D, the alignment image 715 is in the shape of an“H.” Thus, when the interpupillary distance is properly adjusted, thefixation targets on the left and right displays overlap to form an “H”.Other alignment images 715 may be provided.

With reference to FIG. 8, there is illustrated an embodiment of thecomputer system 104. In the illustrated embodiment, the computer system104 can comprise a scan control and analysis module 824 configured tocontrol the scanning operations performed by the main body 106. Thecomputer system 104 can also comprise a fixation marker control system822 configured to display a fixation marker visible by the user frommain body 106. In certain embodiments, the fixation marker is displayedas an “X,” a dot, a box, or the like. The fixation marker can beconfigured to move horizontally, vertically, diagonally, circularly, ora combination thereof. The fixation marker can be repositioned quicklyto relocate the beam location on the retina as the eye repositionsitself. The computer system 104 can also comprise a focus adjust module820 for automatically adjusting the focusing lenses in the main body 106as further discussed herein. The computer system 104 can also comprise aZ positioning module 818 for automatically adjusting the Z offset asherein discussed.

Referring to FIG. 8, the computer system 104 comprises in theillustrative embodiment a disease risk assessment/diagnosis module 808for storing and accessing information, data, and algorithms fordetermining, assessing the risk or likelihood of disease, and/orgenerating a diagnosis based on the data and/or measurements obtainedfrom scanning the eyes of the user. In one embodiment, the scan controland analysis module 824 is configured to compare the data received fromthe main body 106 to the data stored in the disease riskassessment/diagnosis module 808 in order to generate a risk assessmentand/or diagnosis of disease in the eyes of the user as furtherillustrated. The computer system 104 can also comprise an image/scansdatabase configured to store images and/or scans generated by the mainbody 106 for a plurality of users, and to store a unique identifierassociated with each image and/or scan. In certain embodiments, the scancontrol and analysis module 824 uses historical images and/or scans of aspecific user to compare with current images and/or scans of the sameuser to detect changes in the eyes of the user. In certain embodiments,the scan control and analysis module 824 uses the detected changes tohelp generate a risk assessment and/or diagnosis of disease in the eyesof the user.

In the illustrative embodiment shown in FIG. 8, the computer system 104can comprise a user/patient database 802 for storing and accessingpatient information, for example, user name, date of birth, mailingaddress, residence address, office address, unique identifier, age,affiliated doctor, telephone number, email address, social securitynumber, ethnicity, gender, dietary history and related information,lifestyle and/or exercise history information, use of corrective lens,family health history, medical and/or ophthalmic history, priorprocedures, or other similar user information. The computer system 104can also comprise a physician referral database for storing andaccessing physician information, for example, physician name, physiciantraining and/or expertise/specialty, physician office address, physiciantelephone number and/or email address, physician schedulingavailability, physician rating or quality, physician office hours, orother physician information.

In reference to FIG. 8, the computer system 104 can also comprise a userinterface module 805 (which can comprise without limitation commonlyavailable input/output (I/O) devices and interfaces as described herein)configured to communicate, instruct, and/or interact with the userthrough audible verbal commands, a voice recognition interface, a keypad, toggles, a joystick handle, switches, buttons, a visual display,touch screen display, etc. or a combination thereof. In certainembodiments, the user interface module 805 is configured to instructand/or guide the user in utilizing and/or positioning the main body 106of the optical coherence tomography system 100. The computer system 104can also comprise a reporting/output module 806 configured to generate,output, display, and/or print a report (for example, FIGS. 10A and 10B)comprising the risk assessment and/or diagnosis generated by the diseaserisk assessment/diagnosis module 808. In other embodiments, the reportcomprises at least one recommended physician to contact regarding therisk assessment.

Referring to FIG. 8, the computer system 104 can also comprise anauthentication module 816 for interfacing with user card reader system112, wherein a user can insert a user identification card into the usercard reader system 112. In certain embodiments, the authenticationmodule 816 is configured to authenticate the user by reading the datafrom the identification card and compare and/or store the informationwith the data stored in the user/patient database 802. In certainembodiments, the authentication module 816 is configured to read orobtain the user's insurance information from the user's identificationcard through the user card reader system 112. The authentication module816 can be configured to compare the user's insurance information withthe data stored in the insurance acceptance database 828 to determinewhether the user's insurance is accepted or whether the user's insurancecompany will pay for scanning the user's eyes. In other embodiments, theauthentication module communicates with the billing module 810 to send amessage and/or invoice to the user's insurance company and/or devicemanufacturer to request payment for performing a scan of the patient'seyes. The card can activate one or more functions of the machineallowing the user, for example, to have a test performed or receiveoutput from the machine. In other embodiments, the billing module 810 isconfigured to communicate with the user interface module 805 to requestpayment from the user to pay for all or some (for example, co-pay) ofthe cost for performing the scan. In certain embodiments, the billingmodule 810 is configured to communicate with the user card reader system112 to obtain card information from the user's credit card, debit card,gift card, or draw down credit stored on the user's identification card.Alternatively, the billing module 810 is configured to receive paymentfrom the user by communicating and/or controlling an interface devicefor receiving paper money, coins, tokens, or the like. Alternatively,the billing module 810 is configured to receive payment from the user bycommunicating with the user's mobile device through Bluetooth® or othercommunications protocols/channels in order to obtain credit cardinformation, billing address, or to charge the user's mobile networkservice account (for example, the cellular carrier network).

With reference to FIG. 8, the user card may be used by insurers to trackwhich users have used the system. In one embodiment, the system canprint (on the face of the card) or store (in a chip or magnetic stripe)the scan results, risk assessment, and/or report directly onto or intothe card that the patient inserts into the system (wherein the card isreturned to the user). The system can be configured to store multiplescan results, risk assessments, and/or reports, and/or clear prior scanresults, risk assessments, and/or reports before storing new informationon the magnetic stripe. In certain embodiments, the calculation of therisk assessment is performed by the system (for example, scanninganalysis module 824). In certain embodiments, the calculated riskassessment is transmitted a centralized server system (for example,remote systems 110) in another location that provides the results via aweb page to physicians, users, patients, or the like. The centralizedserver system (for example, remote system 110) allows the user,patients, or doctors to enter their card code to see the results whichare saved in the centralized database.

In the example embodiment of FIG. 8, the computer system 104 cancomprise a network interface 812 and a firewall 814 for communicatingwith other remote systems 110 through a communications medium 108. Otherremote systems 110 can comprise without limitation a system for checkingthe status/accuracy of the optical coherence tomography system 100; asystem for updating the disease risk assessment/diagnosis database 808,the insurance acceptance database 828, the physician referral database804, and/or the scan control and analysis module 824. In certainembodiments, the computer system 104 can be configured to communicatewith a remote system 110 to conduct a primary and/or secondary riskassessment based on the data from scanning the user's eyes with the mainbody 106.

Referring to FIG. 8, the remote system 110 can be configured to remotelyperform (on an immediate, delayed, and/or batch basis) a risk assessmentand/or diagnosis and transmit through a network or communications mediumthe risk assessment, diagnosis, and/or report to the computer system 104for output to the user using output device 102. In certain embodiments,the output device 102 is configured to display the risk assessment,diagnosis, and/or report as a webpage that can be printed, emailed,transmitted, and/or saved by the computer system 104. The remote system110 can also be configured to transmit through a network orcommunications medium the risk assessment, diagnosis, and/or report tothe user's (or doctor) cellular phone, computer, email account, fax, orthe like.

With reference to FIG. 9, there is shown an illustrated method of usingthe optical coherence tomography system 100 to self-administer an OCTscan of the user's eyes and obtain a risk assessment or diagnosis ofvarious diseases and ailments. The process begins at block 901 whereinthe user approaches the optical coherence tomography system 100 andactivates the system, by for example pushing a button or typing in aactivation code or anonymous identification number. In otherembodiments, the user interface module 805 instructs users at block 901to first insert an identification card or anonymous coded screening cardin user card reader system 112 to activate the system. The system canalso be activated at block 901 when users insert their useridentification card in user card reader system 112. Other means ofactivating the system are possible as well as, including withoutlimitation, a motion sensor, a weight sensor, a radio frequencyidentification (RFID) device, or other actuator to detect the presenceof the user. Alternatively, the optical tomography system 100 can beactivated when the billing module 810 detects that the user has insertedpaper money, coins, tokens, or the like into an interface deviceconfigured to receive such payment. Alternatively, the billing module810 can also be configured to activate the optical tomography system 100when the billing module 810 communicates with a user's mobile device inorder to obtain the user's credit card information, billing address, orthe like, or to charge the user's mobile network service account (forexample, the cellular carrier network)

In referring to FIG. 9 at block 902, the user interface module 805 isconfigured to direct the user to attach disposable eyecups onto the mainbody 106, and then position the main body 106 with the disposableeyecups near the eyes of the user and/or support the disposable eyecupsagainst the user's eye socket. The user interface module 805 instructsthe user to engage handle 118 to adjust the distance between the leftand right eyepieces 612, 614 to match or substantially conform to theinterpupillary distance of the user as described with respect to FIGS.6A-6F. After the main body 106 and the interpupillary distance has beenappropriately calibrated and/or adjusted by the user, the user inputsinto or indicates to the user interface module 805 to begin the scan.The scan control and analysis module 824 substantially restrictsmovement or locks the position of the zero gravity arm and/or thedistance between the left and right tubes 612, 614 to begin the scan.

Referring to FIG. 9, the Z module 818 automatically adjusts the z-offsetin the main body 106 at block 906 such that the OCT measurement will beobtained, for example, from tissue in the retina. The Z module 818 mayidentify and/or estimate a position of part of the sample (for example,part of an eye of a user 114) and adjust the location of one or moreoptical components based on the position. One of ordinary skill in theart will appreciate the multitude of ways to perform such an adjustment.For example, the Z module 818 may comprise a motor, such as apiezoelectric motor, to translate the reference mirror/s longitudinallysuch that the optical path length from the beam splitter to the retinais about equal to (within a coherence length of) the optical path lengthin the reference arm. This movement may enable light from the referencearm to interfere with light reflected by a desired portion of the sample(for example, the retina). At block 908, the illustrative methodperforms a focus adjustment using the focus adjustment module 820. Thoseof ordinary skill in the art will also appreciate the differenttechniques for performing such auto-focus calibration. Block 910illustrates an optional test performed by the computer system 104 todetermine the visual functional and acuity of the user's eye. Suchvisual functional and acuity tests will be appreciated by those skilledin the art. In one embodiment, the visual acuity test works with or iscombined with the fixation marker control system 722, and can test botheyes simultaneously or one eye at time. For example, the fixation markerwill initially appear small and then gradually increase in size untilthe user indicates through the user interface module 705 that thefixation marker is visible. Based on the size at which the user canclearly see the fixation marker, fixation marker control system 722 canestimate or determine or assess the visual acuity of the user's eyes(for example, 20/20, 20/40, or the like).

With reference to FIG. 9 at Block 912, the user interface module 805instructs the user to follow the movement of the fixation marker that isvisible to the user from the main body 106. In one embodiment, thefixation marker control 822 is configured to display a fixation markerthat moves horizontally. In some embodiments, the horizontal movement ofthe fixation marker allows the scan control and analysis module 824 toscan the eye vertically as the eye moves horizontally, thus possiblyobtaining a two-dimensional, volume, or raster scan of the eye tissue atissue. Alternatively, the scan control and analysis module 824 and/orthe fixation marker control may cause the fixation marker or the beam tojump or move around to obtain measurements at different laterallocations on the eye.

During the scanning of the eye, the scan control and analysis module 824could be configured to detect at block 913 whether there has been ashift in the position of the main body 106 relative to the user. In oneembodiment, the scan control and analysis module 824 can detect (inreal-time, substantially real-time, or with a delay) whether a shift hasoccurred based on what the values the module 824 expects to receiveduring the scanning process. For example, as the scan control andanalysis module 824 scans the retina, the module 824 expects to detect achange in signal as the scanning process approaches the optic nerve (forexample, based on the location of the fixation target and/or state ofthe scanner(s)). Alternatively, the expected values or the expectedchange in values can also be determined or generated using a nomogram.If the system does not detect an expected signal change consistent witha detection of the optic nerve and/or receives no signal change, thenthe module 824 can be configured to interpret such data as the user isnot tracking properly. Other features, for example, the fovea, or thelike, can be used to determine whether the expected signal is observed.If improper tracking occurs enough (based on, for example, a threshold),the system 100 may request that the user fixate again (using fixationmarker control 822) for another scan. If the foregoing shift detectionprocess does not occur in real-time or substantially real-time, then thesystem can be configured to complete the scan, perform data analysis,and during the analysis the system can be configured to detect whether ashift occurred during the scan. If a substantial shift is detected, thenthe user may be instructed (through visual, audible, or verbalinstructions using the user interface module 805) to sit forward againso another scan can be performed. If the system detects a shift 2 or 3or more times, the system can be configured to refer the user to ageneral eye doctor.

At the end of a scan, the scan control and analysis module 824 can beconfigured to produce a confidence value that indicates how likely thenomograms will be to apply to this patient. For example, if the patienthad borderline fixation, the confidence value might be lower than apatient whose fixation appeared to be good.

In the real-time embodiment, the system can be configured to performrapid cross-correlations between adjacent A-scans or B-scans to makesure the eye is moving somewhat. In some embodiments, the foregoing canbe advantageous for ANSI laser safety standards so as to avoid havingusers stare at the same location with laser energy bombarding the user'sretina. Accordingly, in some embodiments, the system is configured witha laser time-out feature if the system detects no eye moment (forexample, cross-correlations above a certain threshold). In someembodiments, to expedite this process and provide real time analysis infrequency domain OCT, signal data may be analyzed prior to performing anFFT. Other technologies can be used to determine that the user has someeye movement.

If no fixation problem has been detected, the scan control and analysismodule 824 completes the scan of the user's eyes, stores the imageand/or scan data in the images/scans database 826, and analyzes theA-scan data at block 915 to generate/determine a risk assessment and/ordiagnosis at block 916 by accessing the data and/or algorithms stored inthe disease risk assessment/diagnosis database 808. In some embodiments,groups of A-scans, partial or full B scans, or partial or full C-scandata can be analyzed.

As used herein the term “nomogram” generally refers to predictive tools,algorithms, and/or data sets. Nomograms in general can providepredictions for a user based on the comparison of characteristics of theuser with the nomogram. The nomograms are derived, generated,calculated, or computed from a number, for example, hundreds, thousands,or millions of users/patients who exhibited the same condition (normalor diseased). In some embodiments described herein, nomograms comparethe risk of having a disease based on physical characteristics.Accordingly, in some cases, nomograms can provide individualizedpredictions that are relative to risk groupings of patient populationswho share similar disease characteristics. In some embodiments,nomograms can be used to provide the risk estimation or risk assessmenton a 0-100% scale. Alternatively, nomograms used herein can provide anexpected value, for example, at a certain position in the eye there isan expected eye thickness value of 100 microns.

Generally, nomograms have been developed and validated in large patientpopulations and are highly generalizable, and therefore, nomograms canprovide the objective, evidence-based, individualized risk estimation orassessment. Accordingly, nomograms can be used as described herein toempower patients and allow them to better understand their disease.Further, nomograms as used herein can assist physicians with clinicaldecision-making and to provide consistent, standardized and reliablepredictions.

In the illustrative method shown in FIG. 9 at block 917, an eye healthassessment or eye health grade report, as illustrated in FIGS. 10A and10B, is generated for the user by accessing the disease riskassessment/diagnosis database 808. At block 918, the physician referraldatabase 804 is accessed to generate a recommendation of when the usershould visit a physician (for example, within one to two weeks). Thephysician referral database 804 is also accessed to generate, compile alisting of physicians suitable for treating the patient. The physicianreferral list can be randomly generated or selected based on referralfee payments paid by physicians, insurance companies, or based onlocation of the physician relative to the user's present location oroffice/home address, or based on the type of detected disease, or basedon the severity of the detected disease, based on the location orproximity of the system relative the location of the physician, or basedon a combination thereof. At block 919, the report is displayed to theuser by using reporting/output module 806 and output device 102. Incertain embodiments, the report data is stored in the user/patientdatabase 802 for future analysis or comparative analysis with futurescans.

In some embodiments, the main body 106 is not supported by the user 114.For example, the main body 106 may be supported by a free-standingstructure, as shown in FIG. 10A. The user 114 may look into theeyepiece(s). The user 114 may be seated on a seating apparatus, whichmay include a height-adjusting mechanism. The main body 106 maysupported by a height-adjustable support.

In some embodiments, such as those shown in FIGS. 10B-10C, a strap 1005is connected to the main body 106. The strap may function to fully orpartly support the main body 106, as shown in FIG. 10B. The strap 905may be excluded in some embodiments. The main body 106 may be hand heldby the user. In some embodiments, the main body 106 may be supported oneyewear frames. In some embodiments, all of the optics are containedwithin the main body 106 that is directly or indirectly supported by theuser 114. For example, the main body 106 in FIG. 10B may include anoptical coherence tomography system, an alignment system, and a dataacquisition device. The data acquisition device may wirelessly transmitdata to a network or computer system or may use a cable to transfercontrol signals. FIG. 10C is similar to that of FIG. 1 and is supportedby a separate support structure (for example, an zero gravity arm). Insome embodiments, a strap, belt, or other fastener assists in thealignment of the main body 106 with one or both eyes of the user 114.

In some embodiments, as shown in FIG. 10D, the user wears an object 1010connected to the eyepiece. The wearable object 1010 may include ahead-mounted object, a hat or an object to be positioned on a user'shead. As described above, in some embodiments, the main body 106 issupported on an eyewear frame worn by the user like glasses. Thewearable object 1010 may fully or partly support the main body 106and/or may assist in aligning the main body 106 with one or both eyes ofthe user 114.

Referring to FIG. 11A and 11B, there are illustrated two exampleembodiments of the eye health grades and the eye health assessmentreports. With reference to FIG. 11A, the eye health grades report cancomprise without limitation a numeric and/or letter grade for each eyeof the user for various eye health categories, including but not limitedto macular health, optic nerve health, eye clarity, or the like. The eyehealth grades report can also comprise at least one recommendation tosee or consult a physician within a certain period of time, and canprovide at least one possible physician to contact. Data for generatingthe recommendation information and the list of referral physicians arestored in the physician referral database 804. In reference to FIG. 11B,the eye health assessment report can comprise a graphical representationfor each eye of the user for various eye health categories. The reportcan be presented to the user on an electronic display, printed on paper,printed onto a card that the user inserted into the machine,electronically stored on the user's identification card, emailed to theuser, or a combination thereof

With reference to FIG. 12, there is illustrated another embodiment ofthe computer system 104 connected to remote system 110 andbilling/insurance reporting and payment systems 1201. The billing module810 can be configured to communicate with billing/insurance reportingpayment systems 1201 through communications medium 108 in order torequest or process an insurance claim for conducting a scan of theuser's eyes. Based on communications with billing/insurance reportingand payment system 1201, the billing module 810 can also be configuredto determine the amount payable or covered by the user's insurancecompany and/or calculate or determine the co-pay amount to be charge theconsumer. In certain embodiments, the user can interact with the userinterface module 805 to schedule an appointment with the one of therecommended physicians and/or schedule a reminder to be sent to the userto consult with a physician. The computer system 104 or a remote system110 can be configured to send the user the reminder via email, textmessage, regular mail, automated telephone message, or the like.

Computing System

In some embodiments, the systems, computer clients and/or serversdescribed above take the form of a computing system 1300 shown in FIG.13, which is a block diagram of one embodiment of a computing system(which can be a fixed system or mobile device) that is in communicationwith one or more computing systems 1310 and/or one or more data sources1315 via one or more networks 1310. The computing system 1300 may beused to implement one or more of the systems and methods describedherein. In addition, in one embodiment, the computing system 1300 may beconfigured to process image files. While FIG. 13 illustrates oneembodiment of a computing system 1300, it is recognized that thefunctionality provided for in the components and modules of computingsystem 1300 may be combined into fewer components and modules or furtherseparated into additional components and modules.

Client/Server Module

In one embodiment, the system 1300 comprises an image processing andanalysis module 1306 that carries out the functions, methods, and/orprocesses described herein. The image processing and analysis module1306 may be executed on the computing system 1300 by a centralprocessing unit 1304 discussed further below.

Computing System Components

In one embodiment, the processes, systems, and methods illustrated abovemay be embodied in part or in whole in software that is running on acomputing device. The functionality provided for in the components andmodules of the computing device may comprise one or more componentsand/or modules. For example, the computing device may comprise multiplecentral processing units (CPUs) and a mass storage device, such as maybe implemented in an array of servers.

In general, the word “module,” as used herein, refers to logic embodiedin hardware or firmware, or to a collection of software instructions,possibly having entry and exit points, written in a programminglanguage, such as, for example, Java, C or C++, or the like. A softwaremodule may be compiled and linked into an executable program, installedin a dynamic link library, or may be written in an interpretedprogramming language such as, for example, BASIC, Perl, Lua, or Python.It will be appreciated that software modules may be callable from othermodules or from themselves, and/or may be invoked in response todetected events or interrupts. Software instructions may be embedded infirmware, such as an EPROM. It will be further appreciated that hardwaremodules may be comprised of connected logic units, such as gates andflip-flops, and/or may be comprised of programmable units, such asprogrammable gate arrays or processors. The modules described herein arepreferably implemented as software modules, but may be represented inhardware or firmware. Generally, the modules described herein refer tological modules that may be combined with other modules or divided intosub-modules despite their physical organization or storage.

In one embodiment, the computing system 1300 also comprises a mainframecomputer suitable for controlling and/or communicating with largedatabases, performing high volume transaction processing, and generatingreports from large databases. The computing system 1300 also comprises acentral processing unit (“CPU”) 1304, which may comprise a conventionalmicroprocessor. The computing system 1300 further comprises a memory1305, such as random access memory (“RAM”) for temporary storage ofinformation and/or a read only memory (“ROM”) for permanent storage ofinformation, and a mass storage device 1301, such as a hard drive,diskette, or optical media storage device. Typically, the modules of thecomputing system 1300 are connected to the computer using a standardsbased bus system. In different embodiments, the standards based bussystem could be Peripheral Component Interconnect (PCI), Microchannel,SCSI, Industrial Standard Architecture (ISA) and Extended ISA (EISA)architectures, for example.

The example computing system 1300 comprises one or more commonlyavailable input/output (I/O) devices and interfaces 1303, such as akeyboard, mouse, touchpad, and printer. In one embodiment, the I/Odevices and interfaces 1303 comprise one or more display devices, suchas a monitor, that allows the visual presentation of data to a user.More particularly, a display device provides for the presentation ofGUIs, application software data, and multimedia presentations, forexample. In the embodiment of FIG. 13, the I/O devices and interfaces1303 also provide a communications interface to various externaldevices. The computing system 1300 may also comprise one or moremultimedia devices 1302, such as speakers, video cards, graphicsaccelerators, and microphones, for example.

Computing System Device/Operating System

The computing system 1300 may run on a variety of computing devices,such as, for example, a server, a Windows server, a Structure QueryLanguage server, a Unix server, a personal computer, a mainframecomputer, a laptop computer, a cell phone, a personal digital assistant,a kiosk, an audio player, and so forth. The computing system 1300 isgenerally controlled and coordinated by operating system software, suchas z/OS, Windows 95, Windows 98, Windows NT, Windows 2000, Windows XP,Windows Vista, Linux, BSD, SunOS, Solaris, or other compatible operatingsystems. In Macintosh systems, the operating system may be any availableoperating system, such as MAC OS X. In other embodiments, the computingsystem 1300 may be controlled by a proprietary operating system.Conventional operating systems control and schedule computer processesfor execution, perform memory management, provide file system,networking, and I/O services, and provide a user interface, such as agraphical user interface (“GUI”), among other things.

Network

In the embodiment of FIG. 13, the computing system 1300 is coupled to anetwork 1310, such as a modem system using POTS/PSTN (plain oldtelephone service/public switched telephone network), ISDN, FDDI, LAN,WAN, or the Internet, for example, via a wired, wireless, or combinationof wired and wireless, communication link 1315. The network 1310communicates (for example, constantly, intermittently, periodically)with various computing devices and/or other electronic devices via wiredor wireless communication links. In the example embodiment of FIG. 13,the network 1310 is communicating with one or more computing systems1317 and/or one or more data sources 1319.

Access to the image processing and analysis module 1306 of the computersystem 1300 by remote computing systems 1317 and/or by data sources 1319may be through a web-enabled user access point such as the computingsystems' 1317 or data source's 1319 personal computer, cellular phone,laptop, or other device capable of connecting to the network 1310. Sucha device may have a browser module implemented as a module that usestext, graphics, audio, video, and other media to present data and toallow interaction with data via the network 1310.

The browser module or other output module may be implemented as acombination of an all points addressable display such as a cathode-raytube (CRT), a liquid crystal display (LCD), a plasma display, or othertypes and/or combinations of displays. In addition, the browser moduleor other output module may be implemented to communicate with inputdevices 1303 and may also comprise software with the appropriateinterfaces which allow a user to access data through the use of stylizedscreen elements such as, for example, menus, windows, dialog boxes,toolbars, and controls (for example, radio buttons, check boxes, slidingscales, and so forth). Furthermore, the browser module or other outputmodule may communicate with a set of input and output devices to receivesignals from the user.

The input device(s) may comprise a keyboard, roller ball, pen andstylus, mouse, trackball, voice recognition system, or pre-designatedswitches or buttons. The output device(s) may comprise a speaker, adisplay screen, a printer, or a voice synthesizer. In addition a touchscreen may act as a hybrid input/output device. In another embodiment, auser may interact with the system more directly such as through a systemterminal connected to the score generator without communications overthe Internet, a WAN, or LAN, or similar network.

In some embodiments, the system 1300 may comprise a physical or logicalconnection established between a remote microprocessor and a mainframehost computer for the express purpose of uploading, downloading, orviewing interactive data and databases on-line in real time. The remotemicroprocessor may be operated by an entity operating the computersystem 1300, including the client server systems or the main serversystem, and/or may be operated by one or more of the data sources 1319and/or one or more of the computing systems. In some embodiments,terminal emulation software may be used on the microprocessor forparticipating in the micro-mainframe link.

In some embodiments, computing systems 1317 that are internal to anentity operating the computer system 1300 may access the imageprocessing and analysis module 1306 internally as an application orprocess run by the CPU 1304.

User Access Point

In one embodiment, a user access point comprises a personal computer, alaptop computer, a cellular phone, a GPS system, a Blackberry® device, aportable computing device, a server, a computer workstation, a localarea network of individual computers, an interactive kiosk, a personaldigital assistant, an interactive wireless communications device, ahandheld computer, an embedded computing device, or the like.

Other Systems

In addition to the systems that are illustrated in FIG. 13, the network1310 may communicate with other data sources or other computing devices.The computing system 1300 may also comprise one or more internal and/orexternal data sources. In some embodiments, one or more of the datarepositories and the data sources may be implemented using a relationaldatabase, such as DB2, Sybase, Oracle, CodeBase and Microsoft® SQLServer as well as other types of databases such as, for example, a flatfile database, an entity-relationship database, and object-orienteddatabase, and/or a record-based database.

With reference to FIG. 14A, there is illustrated an example method fordetermining or generating a risk assessment of a disease, such as an eyedisease, thereby allowing the generation of a health grade andrecommended time to see a physician. The example shown in FIG. 14A isfor retinal disease, however, the process and method illustrated can beused for other diseases or eye diseases. In this example, the scancontrol and analysis module 824 is configured to determine the thicknessof the retina based on the A-scan data derived from the main body 106.This data may include but is not limited to A-scan data from differentA-scans. The scan control and analysis module 824 can also be configuredto access data and algorithms in the disease risk assessment/diagnosisdatabase 808 to calculate the risk assessment of retinal disease basedon the measured thickness of the retina as illustrated by the functioncurve in FIG. 14A. The reporting/output module 806 can be configured tonormalize the calculated risk assessment value into an eye health letteror numerical grade or score. The reporting/output module 806 can also beconfigured to access data and algorithms in the physician referraldatabase 804 to calculate a recommended time to see a physician based onthe calculated risk assessment value.

With reference to FIG. 14B, there is illustrated another example methodor process for determining or generating a risk assessment of disease bycomparing the scan data to the disease risk assessment/diagnosisdatabase 808 comprising, for example, minimum and maximum thickness dataand algorithms, and such minimum and maximum thickness data andalgorithms that can be based on or are in the form of nomograms. Incertain embodiments, the system is configured to generate scan data forportions of the eye scanned to determine thickness of the retina at anyone point, and compare such data to histograms and/or nomograms (forexample, nomograms that show expected thickness at said locationlikelihood of or disease for a given thickness) to derive a riskassessment. The system can also be configured to generate an averagethickness for the entire retina that is scanned, and compare such datato histograms and/or nomograms to derive a risk assessment.

The term “histogram” as used herein generally refers to an algorithm,curve, or data or other representation of a frequency distribution for aparticular variable, for example, retinal thickness. In some cases, thevariable is divided into ranges, interval classes, and/or points on agraph (along the X-axis) for which the frequency of occurrence isrepresented by a rectangular column or location of points; the height ofthe column and/or point along the Y-axis is proportional to or otherwiseindicative of the frequency of observations within the range orinterval. “Histograms,” as referred to herein, can comprise measureddata obtained, for example, from scanning the eyes of a user, or cancomprise data obtained from a population of people. Histograms of theformer case can be analyzed to determine the mean, minimum, or maximumvalues, and analyze changes in slope or detect shapes or curvatures ofthe histogram curve. Histograms of the latter case can be used todetermine the frequency of observation of a measured value in a surveyedsample.

In the instance where an average thickness value is derived from thescan data, there are some conditions/diseases that may be indicated bythickening of the retina in a localized area. Accordingly, such acondition may not significantly affect the average thickness value (forexample, if a substantial portion of the retina is of normal thickness).Therefore, the maximum thickness value may be needed to detect thisabnormal thickening in the retina. In some embodiments, this maximumthickness value may be due to a segmentation error. Accordingly, a morestable way of determining the maximum value may also be to use the valuecorresponding to 95% (or any value between 75% and 99%) maximalthickness. The foregoing can also be applied to minimum retinalthickness or any other value, measurement, and/or detectable conditionin the eye. For example, with minimum retinal thickness, if the user hasa macular hole, there will only be a small area of zero thickness, andpossibly not enough to significantly reduce the average thickness, butdefinitely an abnormality that may be detected.

In other embodiments, the system may be configured to create histogramsof measured thickness and/or measured intensity values and/or slopes orderivatives of intensity values and/or variables to identifyabnormalities. For example, changes or substantial changes in slope(calculated as the derivative of adjacent intensity values) may indicatehyporeflective or hyperreflective structures that may not affect mean oraverage intensity values, but may be indicative of disease orconditions. For example, the system can determine if the distribution ofretinal thicknesses across the measured portion of the retina matchesthat of the normal population. Deviation from such a “normal” histogramwould result in lower health grades/higher risk assessments.

In various embodiments, the methods or processes described herein can beused to determine or generate a risk assessment of maculopathy based,for example, on abnormal thickening of the retina or fovea, the presenceof hyperreflective (bright or high intensity) or hyporeflective (dark orlow intensity) structures in the outer half of the retina, the presenceof hyporeflective (dark) structures in the inner half of the retina, thepresence of irregularities in the contour of the retinal pigmentepithelium that depart from the normal curvature of the eye, or of thepresence of hypertransmission of light through the retinal pigmentepithelium when compared to a database of normal values stored in thedisease risk assessment/diagnosis database 708.

As described above, there are several ways to detect or generate a riskassessment for several diseases or conditions. In certain embodiments,scan data is compared to data found in normal people to identifysimilarities or differences from a nomogram and/or histogram. In otherembodiments, scan data is compared to data found in people with diseasesto identify similarities or differences from nomograms and/orhistograms. The pathognomonic disease features could be indicated bysimilarity to nomograms, for example, images, histograms, or other data,etc. from diseased patients.

In one embodiment, “normal” data (for example, histograms) are createdfor retinal thickness in each region of the retina (optic nerve, fovea,temporal retina) and compare to measured, detected, scanned, orencountered values to these “normal” data (for example, histograms) todetermine relative risks of retinal disease or other diseases. The samecan be performed for nerve fiber layer (NFL) thickness to detectglaucoma. In other embodiments, the detection or generation of a riskassessment for glaucoma is performed or generated by analyzing collinearA-scan data to see if curvilinear thinning indicates the presence ofglaucoma because glaucoma tends to thin the NFL in curvilinear bundles.The NFL radiates out from the optic nerve in a curvilinear fashion likeiron filings around a magnet. Measuring and analyzing a sequence ofA-scan data that follow such a curvilinear path may be useful toidentify such thinning that is characteristic of glaucoma. The analysiscould be centered on and/or around the optic nerve or centered on and/oraround the fovea or elsewhere. In another embodiment, the detectionand/or generation of a risk assessment for glaucoma is performed orgenerated by analyzing the inner surface of the optic nerve to determinethe optic disc cup volume.

The system can also be configured to detect and/or generate a riskassessment for optical clarity wherein the system integrates A-scan datain the Z direction and compares some or all the A-scan data to anomogram value or values, or, for example, a histogram. In general,darker A-scans will probably indicate the presence of media opacities,for example, cataracts, that decrease optical clarity (therefore,increase the subject's risk of having an optical clarity problem, forexample, cataracts).

The system can also be configured to detect or generate risk assessmentsfor retinal pigment epithelium (RPE) features that depart from thenormal curvature of the eye (drusen, retinal pigment epithelialdetachments). Such RPE features can be detected by fitting the detectedRPE layer to a polynomial curve that mimics the expected curvature forthe eye, and using a computer algorithm to analyze, compare, or examinethe difference between these curves. For example with respect to FIG.15, the system can be configured to subtract the polynomial curve thatmimics the expected curvature of the RPE layer 1502 from the detectedRPE layer curve 1504, and analyze and/or compare the resultingdifference/value 1506 with the values (for example, in a histogram ornomogram) from normal and/or diseased eyes to generate a diagnosis orrisk assessment. The foregoing method and process is similar to ameasure of tortuosity in that a bumpy RPE detection will generally havemore deviations from a polynomial curve than smooth RPE detections,which are common in young, healthy people.

Such RPE detection can also be used to detect increased transmissionthrough the RPE which is essentially synonymous with RPE degeneration oratrophy. In certain embodiments, the system is configured to analyze thetissue layer beyond or beneath the RPE layer. Using imaging segmentationtechniques, the RPE layer can be segmented. In certain embodiments, thesystem is configured to add up all of the intensity values beneath theRPE detection. When atrophy is present, there are generally many highvalues beneath the RPE line, which makes the integral value high andwould increase the patient's risk of having a serious macular condition,such as geographic atrophy.

With reference to FIG. 16, the system can also be used to detect orgenerate risk factors for abnormal intensities within the retina. Incertain embodiments, the system is configured to divide the retina intoan inner 1602 and outer 1604 half based on the midpoint between theinternal limiting membrane (ILM) detection 1606 and the RPE detectionlines 1608. In some instances, a blur filter (for example, a Gaussianblur, radial blur, or the like) is applied to the retinal tissue toremove speckle noise and/or other noise. For each the inner and outerretina regions, a first derivative of the intensity values (with respectto position, for example, d/dx, d/dy, or the like) can be calculated todetermine the slope of the curve to differentiate the areas where thereare large changes from dark to bright or vice versa across lateraldimensions of the tissue. For example, intensities or derivatives withinthe retina can be compared to, for example, normal histograms, whereininner retinal hypointensity can be an indicator of cystoid macularedema; or wherein outer retinal hypointensity can be an indicator ofcystoid macular edema, subretinal fluid, or diffuse macular edema; orwherein outer retinal hyperintensity can be an indication of diabetes(which may be the cause of diabetic retinopathy, or damage to the retinadue to, for example, complications of diabetes mellitus), or age-relatedmacular degeneration.

Data from normal patients can used to compile histograms of intensityand/or slope (derivative) data to indicate expected values for normalpeople. Data from people with various diseases can also be placed intohistograms of intensity and/or derivative (slope) values to indicateexpected values for those people with diseases. In certain embodiments,a relative risk will then be developed for each entry on the histogramsuch that this risk can be applied to unknown cases. For example, insome instances, people with 10% of their outer retinal intensity valuesequal to 0 have an 85% chance of having a retinal problem. Accordingly,such users may receive a health grade of 15. In another example, peoplewith any inner retinal points less than 10 have a 100% chance ofdisease, and therefore such users may receive a health grade of 5.

Alternatively, as discussed herein, the foregoing method or process canalso be used to determine or generate a risk assessment of glaucomabased on patterns of thinning of the macular and/or peripapillary nervefiber layer or enlarged cupping of the optic nerve head as compared to adatabase of normal and abnormal values stored in the disease riskassessment/diagnosis database 708. Similarly, to detect or develop arisk assessment for uveitis, a histogram of expected intensity valuesabove the inner retinal surface (in the vitreous), for example, can beused. The presence of large, bright specks (for example, high intensityareas) in the vitreous cavity would indicate possible uveitis and wouldlikely indicate a need for referral. The foregoing method and processcan also be used to determine or generate a risk of eye disease based onthe intensity levels of the image signal as compared to a database ofnormal and abnormal values stored in the disease riskassessment/diagnosis database 708.

In other embodiments, the foregoing method and process can also be usedto determine or generate a risk assessment of uveitis based onhyperreflective features in the vitreous cavity as compared to normaland abnormal hyperreflective features stored in the disease riskassessment/diagnosis database 708. The foregoing method and process canalso be used to determine or generate a risk assessment of anterior eyedisease based on detection of pathognomonic disease features, such ascystoid retinal degeneration, outer retinal edema, subretinal fluid,subretinal tissue, macular holes, drusen, retinal pigment epithelialdetachments, and/or retinal pigment epithelial atrophy, wherein thedetected features are compared with such pathognomonic disease featuresstored in the disease risk assessment/diagnosis database 708. In certainembodiments, the system is configured to perform template matchingwherein the system detects, compares, and/or matches characteristicsfrom A-scans generated from scanning a user, also known as unknownA-scans, with a database of patterns known to be associated with diseasefeatures, such as subretinal fluid, or the like.

With reference to FIGS. 1, 8 and 9, the optical coherence tomographysystem 100 is configured to allow the user to self-administer an OCTscan of the user's eyes without dilation of the eyes, and obtain a riskassessment or diagnosis of various diseases and ailments without theengaging or involving a doctor and/or technician to align the user'seyes with the system, administer the OCT scan and/or interpret the datafrom the scan to generate or determine a risk assessment or diagnosis.In one embodiment, the optical coherence tomography system 100 canperform a screening in less than two minutes, between 2-3 minutes, or2-5 minutes. In certain embodiments, the use of the binocular systemallows the user to self-align the optical coherence tomography system100. The optical coherence system 100 with a binocular system is fastersince it scans both eyes without repositioning and can allow the opticalcoherence tomography system 100 to scan a person's bad eye because theperson's bad eye will follow the person's good eye as the latter tracksthe fixation marker. Accordingly, the optical coherence tomographysystem 100 reduces the expense of conducting an OCT scan, thereby makingOCT scanning more accessible to more people and/or users, and savingmillions of people from losing their eye sight due to eye diseases orailments that are preventable through earlier detection. In oneembodiment, the optical coherence tomography system 100 is configured tohave a small-foot print and/or to be portable, such that the opticalcoherence tomography system 100 can be installed or placed in drugstores, retail malls or stores, medical imaging facilities, grocerystores, libraries, and/or mobile vehicles, buses, or vans, a generalpractitioner's or other doctor's office, such that the optical coherencetomography system 100 can be used by people who do not have access to adoctor.

All of the methods and processes described above may be embodied in, andfully automated via, software code modules executed by one or moregeneral purpose computers or processors. The code modules may be storedin any type of computer-readable medium or other computer storagedevice. Some or all of the methods may alternatively be embodied inspecialized computer hardware.

While the invention has been discussed in terms of certain embodiments,it should be appreciated that the invention is not so limited. Theembodiments are explained herein by way of example, and there arenumerous modifications, variations and other embodiments that may beemployed that would still be within the scope of the present invention.

For purposes of this disclosure, certain aspects, advantages, and novelfeatures of the invention are described herein. It is to be understoodthat not necessarily all such advantages may be achieved in accordancewith any particular embodiment of the invention. Thus, for example,those skilled in the art will recognize that the invention may beembodied or carried out in a manner that achieves one advantage or groupof advantages as taught herein without necessarily achieving otheradvantages as may be taught or suggested herein.

1-83. (canceled)
 84. A method for administering an optical coherence tomography scan, the method comprising: positioning an optical coherence tomography instrument onto at least one user eye, wherein the positioning is performed by the user; and activating the optical coherence tomography instrument by the user to begin the optical coherence tomography scan, wherein the optical coherence tomography instrument is configured to scan the at least one user eye.
 85. (canceled)
 86. The method of claim 84, wherein the optical coherence tomography instrument is activated via a button, keypad, toggle, touch pad, touch sensor, foot pedal, knob, rotating handle, or microphone.
 87. The method of claim 84, wherein activating the instrument comprises entering an input by the user.
 88. The method of claim 84, wherein activating the instrument comprises using a card and a card reader, wherein the card reader is configured to read the card.
 89. The method of claim 88, wherein the card comprises user identification data.
 90. The method of claim 84, wherein activating the instrument comprises triggering an actuator by the user, wherein the actuator is configured to detect the presence of the user near the optical coherence tomography instrument.
 91. The method of claim 90, wherein the actuator is a motion sensor, a weight sensor, and/or a radio frequency identification device.
 92. The method of claim 84, wherein activating the instrument comprises rendering payment by the user to an interface device.
 93. The method of claim 84, wherein activating the instrument comprises interfacing by the user a mobile phone of the user's with a billing module, such that the billing module obtains user data.
 94. The method of claim 93, wherein the user data is credit card information and/or a billing address.
 95. An optical coherence tomography system for providing a self-administered scan, the system comprising: an eyepiece for receiving at least one eye of a user; a light source that outputs light that is directed through the eyepiece into the at least one eye of the user; an interferometer configured to produce optical interference using light reflected from the at least one eye of the user; an optical detector disposed so as to detect the optical interference; and electronics coupled to the detector and configured to provide an output based on optical coherence tomography measurements obtained using the interferometer; wherein the scan is configured to be activated by the user.
 96. The optical coherence tomography system of claim 95, wherein the scan is configured to be activated by the user via a button, keypad, toggle, touch pad, touch sensor, foot pedal, knob, rotating handle, or microphone.
 97. The optical coherence tomography system of claim 95, further comprising: a user interface module configured to: receive an input entered by the user; and activate the scan based at least in part on the input entered by the user, wherein the input comprises an activation code or an identification number.
 98. The optical coherence tomography system of claim 95, further comprising: a card reader configured to: read user identification data from a card; and activate the scan based at least in part on the user identification data read from the card.
 99. The optical coherence tomography system of claim 98, wherein the user identification data comprises the name, the birth date, and/or the billing address of the user.
 100. The optical coherence tomography system of claim 95, further comprising: an actuator configured to detect a presence of the user near the optical coherence tomography system, said scan being activated based at least in part on an indication of the presence of the user near the optical coherence tomography system.
 101. The optical coherence tomography system of claim 100, wherein the actuator is a motion sensor, a weight sensor, or a radio frequency identification device.
 102. The optical coherence tomography system of claim 95, further comprising: a user interface module configured to: receive payment rendered by the user; and activate the scan based at least in part on the payment rendered by the user.
 103. The optical coherence tomography system of claim 95, further comprising: a billing module configured to: interface with a mobile phone of the user's; and obtain user data based at least in part on the interface with the mobile phone of the user's.
 104. The optical coherence tomography system of claim 103, wherein the user data is credit card information and/or a billing address. 